The Chinese patent application No. CN1355727A relates to an adsorbing composition comprising zinc oxide, silica, alumina and nickel or cobalt, and a process for producing this adsorbing composition. According to this process, a carrier containing zinc oxide, silica, and alumina is firstly produced, and then nickel is introduced thereto by an impregnation method. This adsorbing composition can be used in removing sulfur from a fcc gasoline or a diesel fuel.
According to the Chinese patent laid open No. CN1208124C, an adsorbent carrier comprising zinc oxide, expanded perlite, and alumina is impregnated with a promoter metal like cobalt and nickel, and then at a suitable temperature, the promoter is reduced, so as to obtain an adsorbent for use in removing sulfides from a fcc gasoline.
The prior art adsorbents, when used under a hydrogen atmosphere for removing sulfur from gasoline, it is unavoidable to reduce the octane number due to saturation of olefins.
The Chinese patent application No. CN101433821A mentions an adsorbent for removing sulfur from hydrocarbon oils, including a rare earth faujasite, an active metal oxide and a carrier, wherein the carrier includes alumina and zinc oxide, wherein the rare earth faujasite is previously mixed with the carrier and molded into porous solid particles, and then the active metal components are introduced into the porous solid particles, to obtain the adsorbent.
The Chinese patent application No. CN101434854A mentions an adsorbent for removing sulfur from light hydrocarbon oils, including a phosphorus modified rare earth faujasite, an active metal oxide and a carrier including alumina and zinc oxide, wherein a rare earth faujasite is previously modified by phosphorus, and then mixed with the carrier, and then molded into porous solid particles, and then the active metal components are introduced into the porous solid particles, to obtain the adsorbent.
The prior art adsorbents intend to increase the octane number of gasoline by comprising a shape selective molecular sieve in favor of isomerization, however, suffers from the problems of lacking a suitable amount of promoter metals and sulfur reservoirs, resulting in an adsorbent having an insufficient desulfurization activity.
In view of this, there still remains a need in the prior art for a desulfurization adsorbent, which exhibits a high desulfurization adsorbing activity, and at the same time, increases the octane number of the desulfurizated product.